1. Field of the Invention
The present invention relates to a data handling apparatus capable of writing and/or reading data in and/or from a storage medium such as a magnetic disk, an optical disk and a magneto-optical disk. In particular, the present invention relates to a data handling apparatus capable of writing and/or reading data in and/or from a data storage disk which is housed in a disk cartridge having a slidable shutter.
2. Description of the Related Art
As is conventionally known, for reading out data stored in a magnetic disk and/or writing data in the disk, use may be made of a magnetic head which is brought into facing relation to the disk. Such a magnetic head may be formed as a slider which is arranged to float above the rotating magnetic disk by the action of a fluid wedge formed between the slider and the disk. Similarly, an optical head formed as a floatable slider may be used for transferring data to and from a magneto-optical disk.
Typically, such a floatable slider is supported by an elastic member called xe2x80x9csuspension.xe2x80x9d In operation, the suspension serves to urge the slider toward the rotating data storage disk with a suitable elastic force. As the disk is rotated, air is dragged into a space between the slider and the rotating disk, thereby forming a fluid wedge whose positive pressure causes the slider to float above the disk.
For performing proper data-recording and/or data-reading operation, it is desirable to control the floating amount of the slider, so that the slider is kept floating at a constant distance from the disk, no matter what tracks of the disk the slider is located on. In order to achieve this goal, however, the following problem should be solved.
Supposing that the disk is rotated at a constant angular velocity, the slider unfavorably tends to float to a greater extent when it is located on an outer track than when located on an inner track of the disk. This is because when the slider is located on an outer track, the tangential velocity of the rotating disk relative to the slider becomes higher, whereby the pressure of the fluid wedge formed between the slider and the disk becomes greater.
A conventional technique for overcoming the above problem is disclosed for example in JP-A-61(1986)-253679 and JP-A-5(1993)-334828. According to the teachings of these references, the skew angle of the slider is rendered to become greater as the slider is moved from an inner track to an outer track of the disk. (Here, the skew angle is defined as an angle made between the central line of the slider and the tangent line to the track on which the slider is located.)
In this manner, when the slider is moved to an outer track of the disk, the slider tends to receive a smaller floating force from the fluid wedge formed between the slider and the disk. As a result, the difference in floating amount of the slider can be reduced, whether the slider is on an inner track or on an outer track.
Though the teachings of the prior art are useful for adjusting the floating amount of the slider, the conventional technique can be applied only to a hard disk device of a computer, but not to a magneto-optical disk contained in a disk cartridge. Actually, the prior art technique cannot be applied to a cartridge-contained disk because the mechanism of the prior art is difficult (or even impossible) to be made suitably smaller in size.
The present invention has been proposed under the above circumstances, and its objective is to overcome the problem described above.
According to the present invention, there is provided a data handling apparatus comprising:
a rotatable disk provided with at least an innermost track and an outermost track for storing data;
a disk cartridge for housing the disk, the disk cartridge being formed with an opening for exposure of a portion of the disk, the opening being elongated along a first center line extending radially of the disk;
a slider floatable relative to the disk, the slider being provided with a leading portion and a trailing portion; and
a driving mechanism for moving the slider relative to the disk along a predetermined path;
wherein the predetermined path of the slider and the first center line are non-parallel to each other.
According to a preferred embodiment, the slider may have a second center line with respect to which the slider is substantially symmetrical. In this case, the second center line of the slider may be arranged to substantially coincide with a tangent line to the innermost track of the disk when the slider is located on the innermost track.
According to another preferred embodiment, the second center line of the slider may be inclined inward relative to the tangent line to the innermost track of the disk when the slider is located on the innermost track.
Preferably, the slider located on the outermost track may be positioned closer to the first center line than the slider located on the innermost track is.
The slider may be provided with a first objective lens. In this case, the first objective lens may be positioned closer to the trailing portion of the slider than to the leading portion thereof.
Preferably, the driving mechanism may include an actuator supporting a second objective lens. In this case, the first and the second objective lenses may be arranged to work together to provide a lens system.
It is possible for the slider to comprise a magnetic head.
Other objects, features and advantages of the present invention will become clearer from the following detailed description given with reference to the accompanying drawings.